Re: OpenPGP Minutes / Quick Summary

[Jon Callas <[e-mail]>]

On 20 Jul 2006, at 1:45 PM, <[e-mail]> <[e-mail]> wrote:

> a minor issue,
> is that there for some objects, there is no 'generic' OpenPGP
> object form that is identical for all OpenPGP implementations,
> (there is only a more generalized form of the packet types,
> sequence, etc.)
>
> the actual final form of the openPGP object varies somewhat with
> the implementation,
> (although each implementation can work with the forms of the
> other),
>
>
> an example of this,
> would be a message encrypted to Alice's v4 RSA key:
>
> in PGP,
> the message block armor begins with 'qA'
>
> in GnuPG,
> the same message encrypted to the same key,
> begins with 'hQ'
>

Forgive me for agreeing differently. :-)

In the case that you give, the difference is that PGP uses a marker  
packet and GnuPG doesn't. What you need to document is the existence  
of the marker packet. You might do it by creating one with  
implementation X and the other with Y, but the difference is the  
marker packet.

Similarly, we ought to give an example of different length types, old/ 
new header, and so on. Those, however, might not track systems.

(I just put in a note in the PGP bug database that says PGP should  
consider not doing marker packets.)


> it might be useful to list both variations as examples
> of the discretionary leeway available to implementors,
> and how they can leave little telltale signs that distinguish
> their own implementations,
> as long as the essentials of intercompatibility are preserved
>
>
> in order to not 'overdo' the trivia,
> i can start with a tentative list of the example types,
> and then have people suggest either addtions or deletions from the
> list
>

Yes, that's all part of the OpenPGP Bestiary, as I've been calling it.

	Jon